HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

 

DAILY REPORT      #5075

 

PERIOD COVERED: 5am April 14 - 5am April 15, 2010 (DOY 104/09:00z-105/09:00z)

 

OBSERVATIONS SCHEDULED

 

ACS/WFC 11995

 

CCD Daily Monitor (Part 2)

 

This program comprises basic tests for measuring the read noise and dark

current of the ACS WFC and for tracking the growth of hot pixels. The

recorded frames are used to create bias and dark reference images for

science data reduction and calibration. This program will be executed

four days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To

facilitate scheduling, this program is split into three proposals. This

proposal covers 320 orbits (20 weeks) from 1 February 2010 to 20 June

2010.

 

ACS/WFC/WFC3/IR 11802

 

WFC3/IR Observations of Strongly Lensing Clusters

 

We propose WFC3/IR observations of the massive lensing clusters Abell

1689 and Abell 1703 to constrain the properties of both cluster and

background field galaxies. The dataset will also help constrain the

photometric redshift of A1689-zD1, the bright galaxy candidate at z~7.6.

 

NIC2/WFC3/IR 11548

 

Infrared Imaging of Protostars in the Orion A Cloud: The Role of

Environment in Star Formation

 

We propose NICMOS and WFC3/IR observations of a sample of 252 protostars

identified in the Orion A cloud with the Spitzer Space Telescope. These

observations will image the scattered light escaping the protostellar

envelopes, providing information on the shapes of outflow cavities, the

inclinations of the protostars, and the overall morphologies of the

envelopes. In addition, we ask for Spitzer time to obtain 55-95 micron

spectra of 75 of the protostars. Combining these new data with existing

3.6 to 70 micron photometry and forthcoming 5-40 micron spectra measured

with the Spitzer Space Telescope, we will determine the physical

properties of the protostars such as envelope density, luminosity,

infall rate, and outflow cavity opening angle. By examining how these

properties vary with stellar density (i.e. clusters vs. groups vs.

isolation) and the properties of the surrounding molecular cloud; we can

directly measure how the surrounding environment influences protostellar

evolution, and consequently, the formation of stars and planetary

systems. Ultimately, this data will guide the development of a theory of

protostellar evolution.

 

STIS/CC 11845

 

CCD Dark Monitor Part 2

 

Monitor the darks for the STIS CCD.

 

STIS/CC 11847

 

CCD Bias Monitor-Part 2

 

Monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,

and 1x1 at gain = 4, to build up high-S/N superbiases and track the

evolution of hot columns.

 

STIS/CCD/MA2 11568

 

A SNAPSHOT Survey of the Local Interstellar Medium: New NUV Observations

of Stars with Archived FUV Observations

 

We propose to obtain high-resolution STIS E230H SNAP observations of

MgII and FeII interstellar absorption lines toward stars within 100

parsecs that already have moderate or high-resolution far-UV (FUV),

900-1700 A, observations available in the MAST Archive. Fundamental

properties, such as temperature, turbulence, ionization, abundances, and

depletions of gas in the local interstellar medium (LISM) can be

measured by coupling such observations. Due to the wide spectral range

of STIS, observations to study nearby stars also contain important data

about the LISM embedded within their spectra. However, unlocking this

information from the intrinsically broad and often saturated FUV

absorption lines of low-mass ions, (DI, CII, NI, OI), requires first

understanding the kinematic structure of the gas along the line of

sight. This can be achieved with high resolution spectra of high-mass

ions, (FeII, MgII), which have narrow absorption lines, and can resolve

each individual velocity component (interstellar cloud). By obtaining

short (~10 minute) E230H observations of FeII and MgII, for stars that

already have moderate or high- resolution FUV spectra, we can increase

the sample of LISM measurements, and thereby expand our knowledge of the

physical properties of the gas in our galactic neighborhood. STIS is the

only instrument capable of obtaining the required high resolution data

now or in the foreseeable future.

 

WFC3/ACS/IR 11584

 

Resolving the Smallest Galaxies with ACS

 

An order of magnitude more dwarf galaxies are expected to inhabit the

Local Group, based on currently accepted galaxy formation models, than

have been observed. This discrepancy has been noted in environments

ranging from the field to rich clusters, with evidence emerging that

lower density regions contain fewer dwarfs per giant than higher density

regions, in further contrast to model predictions. However, there is no

complete census of the faintest dwarf galaxies in any environment. The

discovery of the smallest and faintest dwarfs is hampered by the

limitations in detecting such compact or low surface brightness

galaxies, and this is compounded by the great difficulty in determining

accurate distances to, or ascertaining group membership for, such faint

objects. The M81 group provides a powerful means for establishing

membership for faint galaxies in a low density region. With a distance

modulus of 27.8, the tip of the red giant branch (TRGB) appears at I ~

24, just within the reach of ground based surveys. We have completed a

65 square degree survey in the region around M81 with the CFHT/MegaCam.

Half of our survey was completed before Cycle 16 and we were awarded

time with WFPC2 to observe 15 new candidate dwarf galaxy group members

in F606W and F814W bands in order to construct color-magnitude diagrams

from which to measure accurate TRGB distances and determine star

formation and metallicity histories. The data obtained show that 8 - 9

of these objects are galaxies at the same distance as M81. In completing

our survey, we have discovered an additional 8 candidate galaxies we

propose to image with ACS in order to measure TRGB distances and

establish membership. We also wish to re-observe our smallest candidate

group member and a tidal dwarf candidate with deeper observations made

possible with ACS. Once membership has been established for this second

set of candidates, we will have a complete census of the dwarf galaxy

population in the M8 group to M_r ~ -10, allowing us to obtain a firm

measurement of the luminosity function faint-end slope, and, combined

with previous HST data, to provide a complete inventory of the age and

abundance properties for the collapsed core of the M81 group.

 

WFC3/UVIS 11905

 

WFC3 UVIS CCD Daily Monitor

 

The behavior of the WFC3 UVIS CCD will be monitored daily with a set of

full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K

subarray biases are acquired at less frequent intervals throughout the

cycle to support subarray science observations. The internals from this

proposal, along with those from the anneal procedure (Proposal 11909),

will be used to generate the necessary superbias and superdark reference

files for the calibration pipeline (CDBS).

 

WFC3/UVIS/IR 11662

 

Improving the Radius-Luminosity Relationship for Broad-Lined AGNs with a

New Reverberation Sample

 

The radius-luminosity (R-L) relationship is currently the fundamental

basis for all techniques used to estimate black hole masses in AGNs, in

both the nearby and distant universe. However, the current R-L

relationship is based on 34 objects that cover a limited range in black

hole mass and luminosity. To improve our understanding of black hole

growth and evolution, the R-L relationship must be extended to cover a

broader range of black hole masses using the technique known as

reverberation mapping. To this end, we have been awarded an

unprecedented 64 nights on the Lick Observatory 3-m telescope between

March 24 and May 31, 2008, to spectroscopically monitor 12 AGNs in order

to measure their black hole masses. To properly determine the

luminosities of these 12 AGNs, we must correct them for their

host-galaxy starlight contributions using high-resolution images.

Previous work by Bentz et al. (2006) has shown that the starlight

correction to AGN luminosity measurements is an essential component to

interpreting the R-L relationship. The correction will be substantial

for each of the 12 sources we will monitor, as the AGNs are relatively

faint and embedded in nearby, bright galaxies. Starlight corrections are

not possible with ground-based images, as the PSF and bulge

contributions become indistinguishable under typical seeing conditions,

and adaptive optics are not yet operational in the spectral range where

the corrections are needed. In addition, spectral decompositions are

very model-dependent and are limited by the degree of accuracy to which

we understand emission processes and stellar populations in galaxies.

Without correcting for starlight, we will be unable to apply the results

of our Spring 2008 campaign to the body of knowledge from previous

reverberation mapping work. Therefore, we propose to obtain high

resolution, high dynamic range images of the host galaxies of the 12

AGNs in our ground-based monitoring sample, as well as one white dwarf

which will be used as a PSF model.

 

STIS/CCD 11849

 

STIS CCD Hot Pixel Annealing

 

This purpose of this activity is to repair radiation induced hot pixel

damage to the STIS CCD by warming the CCD to the ambient instrument

temperature and annealing radiation damaged pixels. Radiation damage

creates hot pixels in the STIS CCD Detector. Many of these hot pixels

can be repaired by warming the CCD from its normal operating temperature

near -83 C to the ambient instrument temperature (~ +5 C) for several

hours. The number of hot pixels repaired is a function of annealing

temperature. The effectiveness of the CCD hot pixel annealing process is

assessed by measuring the dark current behavior before and after

annealing and by searching for any window contamination effects.

 

FLIGHT OPERATIONS SUMMARY:

 

Significant Spacecraft Anomalies: (The following are preliminary reports

of potential non-nominal performance that will be investigated.)

 

HSTARS:

12247 - STIS CCD Dark Image Shifted One Column to the Left

 

           The STIS Science Team has reported the one dark science image taken on

           2010/003/13:37:00.000 for Proposal 11849 - STIS CCD Hot Pixel Annealing.

 

 

COMPLETED OPS REQUEST: (None)

 

COMPLETED OPS NOTES: (None)

 

                      SCHEDULED  SUCCESSFUL             

FGS GSAcq              12             12               

FGS REAcq               8               8       

OBAD with Maneuver 6               6       

 

SIGNIFICANT EVENTS: (None)